1. Field of the Invention
This invention relates generally to aircraft door assemblies and, more particularly, to a hinge mechanism for connecting an aircraft door to a fuselage.
2. Related Art
An important part of any door assembly is the hinge assembly that connects the door to the adjacent aircraft fuselage structure. One particular type of hinge assembly is arranged so that, when the door is opened, the door physically separates from the surrounding structure and is translated out and away from the body while the door itself maintains a relatively parallel orientation to the longitudinal axis of the aircraft fuselage. The hinge also translates the door forward to provide a clear opening into the aircraft as the door swings away from the body. When the door is completely open, the inside face of the door is adjacent the outer skin of the aircraft.
Many hinge assemblies used with translating-motion-type aircraft doors include both a structural hinge for securing the door to the aircraft and a mechanical linkage that provides a second door-to-fuselage connection. The mechanical linkage is employed to control the rotational orientation of the door along its vertical axis so that, as the door is moved away from the fuselage, the door remains generally parallel to the outer skin of the aircraft. If the movement of the door was not controlled, the door would swing free at the end of the hinge and be difficult to maneuver and/or strike the outer skin of the fuselage.
What is needed is a mechanism configured to use a small number of fittings and links to provide a more rigid linkage with less overall stretching or flex than existing systems.